As is known in the prior art, load cells generally function in pure axial tension and compression. In certain applications, off axis loads are involved. These loads can result in inaccurate measurements or could, in fact, damage the load cell. Many commercial load cells use a metal diaphragm fitted with foil strain gages. These diaphragms result in larger diameter designs. They also use thin membranes to mitigate off-axis loads. The membranes are situated on both ends of the load cell and are usually between the fixed outer rim and the active central core. In any event, to minimize the size of a tension/compression load cell, a load beam fitted with strain gauges is employed. The beam is small in size (as, for example, 0.085×0.270 inches). As indicated, the load beam basically is a relatively thin platform and is the active sensing element. The beam is designed for maximum micro strain on the gages located on the beam at maximum rated load. In tension or compression, the load beam can accept off axis perturbations to about 36 inch pounds before yielding and deforming the beam. These loads will be encountered especially in the compression mode, where beam-buckling can also occur. In any event, the critical buckling load is 16 times less, without side support for guiding the load beam in compression.
It is apparent that there is a need in operating such beam transducers to prevent the beam from bending and therefore, subjecting the beam to side loads. The side loads are sensed by the strain gages employed on the beam and added to the load cell readings, resulting in erroneous data.
It is therefore an object of the present invention to eliminate the side load readings without effecting the axial tension and compression forces impressed on the load beam.